Rotary drill bit



5 Sept 1927 J. R. CUBLEY ROTARY DRILL BIT Filed Jan. 12, 1925 d. R. GUBLEY.

w/Ziv ylali.

Patented Sept. 6, a

1,641,321 PATENT OFFICE.

HJAMES R I. CUBLEY, 0F EM PIRE CITY, OKLAHOMA.

ROTARY DRILL BIT.

. Application filed January 12, 1923. Serial No. 612,237.

My invention relates to rotarydrill bits for oil wells and the like, and',has for its object to provide such a-bit which will cut through hard formations, such as rock, and also throughthe softer formations with equal facility; thereby eliminating the need for changing drill bits from time to time as different formations are reached in the boring operation.

Another object of the invention resides in positioning the water outlets adjacent the' lower end of the bit in order that the descending water will not interfere with the cuttings as they move upwardly through the channels of the bit.

Alfurther object of the invention is the provision of a rotary drill bit in which the channels of the bit increase in cross section toward the top of the bit in order to avoid congestion of the cuttings nd permitting their free passage up througli the channels. In SBCllIlIlg drill bits to the coupling it is always necessary to strike some heavy blows against the upper portion of the bit in order place.

invariably damaged by this hammering, due

that the latter may be securely locked in Drill bits of usual construction are to the fact that a portion of the material of the bit is swagedover the channels at their upper ends, thereby partly closing the chan- 1 nels and preventing the ready upward'flow line 3-3 of Figure 1.

line 4 -4 of Figure 1.

line 6'6 of Figure 1.

of the cuttings; It is an ob'ect of the present invention to overcome t is difficulty by gradually increasing the 'cross sectional area of the channels toward the top of the bit.

Other objects and advantages of the inven-' tion will be apparent from the following description when taken in connection with the accompanying drawings, in which Fi ure .1 is a side elevation of the drill bit, showing the drill coupling in section.

=Figure 2 is an endview of the bit.

Figure '3 is a horizontal section taken on Figure 4 is a horizontal section-takenon Figure 5 is a horizontal seotibntaken on line 5-5 ofFigure 1, and

Figure 6 is'a h'orizontal section taken on Referring to the drawings mamas-"detail the numeral 1 indicates the shaftof the drill out-fit and 2 the coupling" by which the drill bit 3 is connected to the shaft 1.

The drill bit 3 is formed with a neck, or

shank; 4, which is threadedto receive the edges5 are formed are so proportioned and arranged that the cross sectional area of the channels 6 is uniform up to. the point A (Figure 1) and from thereon gradually increases towards the top of the bit so as to provide suflicient space for the passage of the cuttings which rise therethroughand pass upwardly through the hole being bored. Furthermore, the maximum diameter of the bit head is uniform from the bottom up to the line A-A, and from this point upward the maximum diameter of the head gradually decreases. It may be here stated that in attaching drill bits to the shaft it is necessary to hammer the bit at its upper end in hammering swages over a portionof the material of the bit and thereby partly closes the channels through which the cuttings pass. By having the cross sectional area of the channels increased as above described this defect is avoided in the present construction. The .lower end of the bit is formed with a centering point 8 which is formed by the flukes 7 and by cutting back the facets or supporting heels 9 to an angle of about 45 with the horizontal.- These facets 9 are, of course, sharpened on their forward edges and provide the initial cutting edges 10.

Extending downwardly through the body of the drill bit 3 are a plura-lity of water passages 11. These passages open into the channels 6 at a oint adjacent the lower end of the bit,. as in icated at 12. It is of paramount importance that the water be directed to the point of action of the bit without interfering with the ascent of the cuttings. and it is for this reason that the openings 12 are placed as near the lower end of the bit as possible.

Due to wear on the bit during action and during sharpening, the head is gradually as above describetha portion'of the thin wall separating the channel and passage may be IOU cut away, thereby raising the water exit 12 to the desired extent.

From the foregoing description when taken in connection with the accompanying drawings it will be observed that I have provided a bit which maybe used in connection with either hard or soft formations, and also one which permits of a free exit of the cuttings at all times.

In accordance with the patent statutes, I have described what I now believe to be the best embodiment of the invention, but I do not wish to be understood thereby as limiting myself or the scope of the invention, as many changes and modifications may be made without departing from the spirit of the invention; all such I aim to include in the scope of the appendedclaims.

What I claim as new and desire to secure by Letters Patent is:

1. A drill bit including a head portion and a shank, said head portion provided with a single channel on either side thereof, said channels extending substantially longitudinally of the head, fiukes forming said channels, the sides of the flukes forming the walls of the channels being helical surfaces with ae4as21 constantly increasing outward flare until channel bottoms, at the top of the head.

. merging into substantial coincidence with the g thereby increasing the cross-sectional area of the channels.

2. A drill bit including a head portion and a shank, said head portion provided with'a single channel on either side thereof, said channels extending substantially longitudinally of the head, flukes forming said channels, the sides/ of the flukes forming the walls of the channels being-helical surfaces with constantly increasing outward flare until.

merging into substantial coincidence with the channel bottoms at the top of the head,

thereby increasing the cr0ss-sectional area of the channels, said head portion further pro vided with longitudinal passages adjacent the center line of the body portion thereof and opening into said channels adjacent the point of thebit, the wall between said passages and channels being relatively thin, whereby asthe head is shortened through use the position of the passage openings may be raised accordingly.

. JAMS a. CUBLEY. 

